Author Topic: 123 blocks (Read 23346 times)

Roger Beere · « **on:** June 17, 2011, 05:27:22 AM »

Hi all.

I have been struggling through trying to find how to use the site (being a newcommer and thick as pig dung where these new fangled computers are concerned) and I stumbled accross the 123 block topic. I have been model engineering for 25 years ish and have never come accross them. Does anyone have a photo?

It is raining here in Brittany, France. Quite romantic listening to the rain hammering down on the workshop roof, sort of deadens the sound of the swearing whilst I am TRYING to fit the b£$%$&$d water gauge to the traction engine. I could do with a 3/8 X 32 tap for the top fixing and a 3/8 X 33 tap for the bottom.

We are invited to our neighbours 50th wedding doo tomorrow and there is no bar!!! now what's that all about???

Regards

Roger

raynerd · « **Reply #1 on:** June 17, 2011, 05:35:10 AM »

Chris

PekkaNF · « **Reply #2 on:** June 17, 2011, 05:36:55 AM »

See:
http://rotagriponline.com/index.php?option=com_virtuemart&page=shop.browse&category_id=264&Itemid=29

I have set of these
123 Block Set
http://rotagriponline.com/index.php?page=shop.product_details&flypage=shop.flypage&product_id=7660&category_id=264&option=com_virtuemart&Itemid=29

Have to check if the threads are as advertized when I'll get some imperial bolts (3/8-16")! If it fits, maybe I should order that size allthread.

I have only used them on my milling vice to tilt boltted objects.

Pekka

PekkaNF · « **Reply #3 on:** June 17, 2011, 04:13:59 PM »

Right. Went to local bolt shop and bought ONE 3/8-16 bolt, because I didn't want to end a box full of bolt assortment I have no use for.

It did fit perfectly.

Now what? More bolts?

Pekka

Bogstandard · « **Reply #4 on:** June 17, 2011, 08:48:17 PM »

Quote

ONE 3/8-16 bolt

Is that UNC or BSW?

doubleboost · « **Reply #5 on:** June 17, 2011, 09:13:09 PM »

Unc &Whit are very similar but not the same (they are both crap)Compared to the metric equivilent

At least metric comes apart after a few years

The most commonly snapped tap must be 1/4 whit

Bogstandard · « **Reply #6 on:** June 17, 2011, 09:50:16 PM »

The reason that I asked John, is that both UNC & BSW both have the same diameter and pitch (but different thread angles) and sometimes, at a push, can be used with each other as a 'get you home' fix (bodge it up).

So I just asked which thread type it was, just to make sure that the correct information is given, so that people could buy the right ones, and not have to bodge the bolts in.

We will have to differ on the best threads (there has been massive debates on the subject), as sometimes, both the coarse threads of UNC & BSW can be used to great effect when trying to hold a thread in soft or weak materials, like ali, sometimes brass and bronze(depending on type), tufnol and magnesium etc, whereas metric will just strip out when tightening pressure is applied, as the threads are not strong enough.

BTW, if you buy the slightly more expensive versions of the 3-2-1 blocks (in a plastic blow moulded box), they are supplied with the correct sized cap screws, but they still won't go thru the blank holes. I know, I have bought both types.

John

PekkaNF · « **Reply #7 on:** June 18, 2011, 05:07:47 AM »

Quote from: Bogstandard on June 17, 2011, 08:48:17 PM

Quote
ONE 3/8-16 bolt

Is that UNC or BSW?

That was the question I got asked at the shop, but because my head is made out of swiss cheese I didn't write it down and I didn't put it here because I was not sure. I think I hear it was unified, I checked it home with a 60 dec. gauge but the problem is: I never gauged 55 dec. I just don't have experiend on how the difference is. Maybe I'll get adventurous and buy few bots of opposite inclination and compare these.

This bolt looked odd to me. Pretty much all inch based bolts I have seen lately have this american grade marking. This has 8.8 grade, same as metric.

It's an industrial shop next next chance is on Monday, then I'll make it doublesure and take the block and the screw at the shop and ask them.

I'll get back to this when I have facts.

Pekka

tomrux · « **Reply #8 on:** June 18, 2011, 06:27:51 AM »

8.8 is the grade or strength of the bolt. all religions of bolt carry the same grade marking. it gives the yield point of of bolt nut combination

8.8 structural grade

10.6 high strength(high tensile) may also be denoted by three check marks on the head of a bolt. especially so on small bolts

4.4 is normal grade mild steel. normaly not marked.

Nuts are marked with three arcs on one face concentric with the thread if they are high strength otherwise assume normal mild steel

Tom

PekkaNF · « **Reply #9 on:** June 18, 2011, 07:19:08 AM »

Oh, these 8.8 et al grade markings I'm familiar with. Somehow I related tangential lines (check marks?) purely to a american system. Seen them only on aviation and most of those seem to be imperial.

Pekka

DavidA · « **Reply #10 on:** June 18, 2011, 12:46:44 PM »

My own interest in this Whitworth into UNC or vice versa comes from a very (last week) recent problem that arose at work.

The test house needed to do a tensile test on a capscrew that at first appeared to be Whitworth. The lad who was going to do the test was losing his hair as he couldn't get the screw to fit the Whitworth dolly (adaptor) that holds it in the machine.
It dawned on me that it may be a UNC thread; and it was. It was the first UNC thread he had come across .

It went into the dolly about half a turn then stopped.

Solution; We bought a set of UNC taps and made another dolly for the job.

I agree that you could force one into the other if the material was soft and the need great enough. But not into a hardened steel adaptor.

Dave.

PekkaNF · « **Reply #11 on:** June 20, 2011, 12:34:45 PM »

OK. Went shopping today.

MINE has 3/8-16 UNC.

They go clear trough untapped holes and thread on tapped holes - after some gunked up residue has been cleaned off.

Bought 10 bolts each from 25 to 38 mm.

Pekka

stefang · « **Reply #12 on:** June 20, 2011, 04:02:11 PM »

Hi,

Short Question:

Are there 1-2-3 blocks with metric threads out somewhere?

Imperial studs and screws are hard to find over here

Stefan

David Jupp · « **Reply #13 on:** June 20, 2011, 04:20:03 PM »

Surely they would be 25 - 50 - 75 (mm) blocks with metric threads ? Or maybe some other convenient multiples ( 20-40-60 ?) , or are 1-2-3 blocks used even in countries that work entirely in mm ?

No1_sonuk · « **Reply #14 on:** June 20, 2011, 08:24:30 PM »

Stefan,
You might be able to get imperial bolts at reasonable prices from the UK.
No customs charges to Germany.

Shadow · « **Reply #15 on:** June 20, 2011, 09:10:50 PM »

I worked for a short while at a bolt distributor. Rather than rely on my memory I did a search and found this chart (printable).

http://www.nutsandbolts.com/v1-bolt-grade-markings.html

My imported set from MSC has 3/8"x16 UNC.

Bogstandard · « **Reply #16 on:** June 20, 2011, 09:20:38 PM »

http://www.shars.com/products/view/2278/255075_Economy_Block_w_23_holes

But even these have the 3/8 x 16 UNC threads.

AdeV · « **Reply #17 on:** June 21, 2011, 06:55:15 AM »

Has anyone here ever actually USED a bolt in a 1-2-3 block? And if so... what for?

Bogstandard · « **Reply #18 on:** June 21, 2011, 07:17:05 AM »

Ade,

They were originally designed to bolt together, so you could make them up into accurate angle plates etc.

Then the balls up came, and stopped them doing that dead in their tracks.

I don't know if ever there were any manufactured that could be bolted together.

I don't know if the 2-4-6 blocks suffer from the same problem.

John

John Stevenson · « **Reply #19 on:** June 21, 2011, 07:24:35 AM »

Yes they could, I have one original set of Starrett blocks here that are made correctly in that the non threaded holes are 3/8" dead.

Also have two other sets that can't as they are all 3/8" tapping size

I can't comment on the 2 - 4 - 6 blocks as I don't have a set, too big for what I do.

I can see what's happened, these have been sent to China and put on a VMC for machining and to save time they have just used one drill but then they have been copied all over, even being exported to India. Can't see it getting rectified any time soon, if ever.

The factories probably don't even know they are wrong, any feedback goes to a reseller / trading house / importer who just ignores it whilst it doesn't affect sales.

John S.

HS93 · « **Reply #20 on:** June 21, 2011, 08:59:41 AM »

Ok I have read this post several times and even spoke to bogs about it and Had a thought could you not simmply make a couple of special bolts that have the correct thread for the 321 blocks then has a shank that will go through the holes and the the end is threaded on the part that goes through the non threaded part of the block ok the nut will be one size smaller than the main .

sorry about the sketch

peter

Miner · « **Reply #21 on:** June 27, 2011, 06:40:07 PM »

Quote from: doubleboost on June 17, 2011, 09:13:09 PM

Unc &Whit are very similar but not the same (they are both crap)Compared to the metric equivilent
At least metric comes apart after a few years
The most commonly snapped tap must be 1/4 whit

Sorry to nit pick and this is a long ways away from this threads topic but I'm curious and really can't understand this comment. I've run very heavy duty mining equipment for most of my working life, Some of it weighing up to 2000 tons and the majority of it had UNC bolts and threads holding all that weight togeather along with the working stresses involved while operating it. I'll not argue about the theroetical superiority of Metric verses Imperial, Nor do I want to get a bunch of differing opinions about either. But somehow a 60 degree Metric thread form is superior to the Imperial 60 degree thread form so UNC is crap? Metric comes apart but UNC doesn't? Yeah I know you were probably joking but? I do the majority of my work in my shop with Imperial threads so maybe there is something I don't know about Metric.

Pete

Bogstandard · « **Reply #22 on:** June 28, 2011, 02:50:01 AM »

Peter,

You are quite right about making a stepped bolt, and I suppose it might be more accurate and less inconvenient.

The normal way to get around the problem is to use a smaller bolt that goes right thru both tapped and untapped holes.

Your way would do away with having an extra bolt head or nut on one side of the assembled blocks.

John

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Author Topic: 123 blocks (Read 23346 times)